package me.zhengjie.utils.map;

public class GCJ02_WGS84 {
    public static double pi = 3.1415926535897932384626;

    public static double a = 6378245.0;

    public static double ee = 0.00669342162296594323;

    public static LocateInfo wgs84_To_Gcj02(double lat, double lon) {

        LocateInfo info = new LocateInfo();

        if (outOfChina(lat, lon)) {

            info.setChina(false);

            info.setLatitude(lat);

            info.setLongitude(lon);

        }else {

            double dLat = transformLat(lon - 105.0, lat - 35.0);

            double dLon = transformLon(lon - 105.0, lat - 35.0);

            double radLat = lat / 180.0 * pi;

            double magic = Math.sin(radLat);

            magic = 1 - ee * magic * magic;

            double sqrtMagic = Math.sqrt(magic);

            dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);

            dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);

            double mgLat = lat + dLat;

            double mgLon = lon + dLon;

            info.setChina(true);

            info.setLatitude(mgLat);

            info.setLongitude(mgLon);

        }

        return info;

    }

    public static LocateInfo gcj02_To_Wgs84(double lat, double lon) {

        LocateInfo info = new LocateInfo();

        LocateInfo gps = transform(lat, lon);

        double lontitude = lon * 2 - gps.getLongitude();

        double latitude = lat * 2 - gps.getLatitude();

        info.setChina(gps.isChina());

        info.setLatitude(latitude);

        info.setLongitude(lontitude);

        return info;

    }

    private static boolean outOfChina(double lat, double lon) {

        if (lon < 72.004 || lon > 137.8347)

            return true;

        if (lat < 0.8293 || lat > 55.8271)

            return true;

        return false;

    }

    private static double transformLat(double x, double y) {

        double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y

                + 0.2 * Math.sqrt(Math.abs(x));

        ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;

        ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;

        ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;

        return ret;

    }

    private static double transformLon(double x, double y) {

        double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1

                * Math.sqrt(Math.abs(x));

        ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;

        ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;

        ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0;

        return ret;

    }

    private static LocateInfo transform(double lat, double lon) {

        LocateInfo info = new LocateInfo();

        if (outOfChina(lat, lon)) {

            info.setChina(false);

            info.setLatitude(lat);

            info.setLongitude(lon);

            return info;

        }

        double dLat = transformLat(lon - 105.0, lat - 35.0);

        double dLon = transformLon(lon - 105.0, lat - 35.0);

        double radLat = lat / 180.0 * pi;

        double magic = Math.sin(radLat);

        magic = 1 - ee * magic * magic;

        double sqrtMagic = Math.sqrt(magic);

        dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);

        dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);

        double mgLat = lat + dLat;

        double mgLon = lon + dLon;

        info.setChina(true);

        info.setLatitude(mgLat);

        info.setLongitude(mgLon);

        return info;

    }
}
